bytes.fromhex() Method - Python

bytes.fromhex() method converts a hexadecimal string into a bytes object. Each pair of hex digits represents one byte making it useful for decoding hexadecimal-encoded data. For Example:

hex_str = "48656c6c6f20576f726c64"  # Hex representation of "Hello World"
byte_data = bytes.fromhex(hex_str)

print(byte_data)

b'Hello World'

Syntax of bytes.fromhex()

bytes.fromhex(string)

• Parameters: string: A hexadecimal string containing only valid hex characters (0-9, A-F).
• Return: Returns a bytes object containing the decoded binary data.

Converting Hexadecimal Strings to Bytes

When working with hexadecimal-encoded data, bytes.fromhex() helps in decoding it back into a bytes object.

hex_code = "4e6574776f726b"
res = bytes.fromhex(hex_code)

print(res)

b'Network'

Explanation:

• hexadecimal string "4e6574776f726b" corresponds to the word "Network".
• bytes.fromhex(hex_code) decodes the hex string into the bytes object: b'Network'.

Processing Encrypted Data

This method is often used in cryptography or network communication when dealing with encoded binary data.

# cipher_text
s = "5365637265744b6579"

# decoded_cipher
o = bytes.fromhex(s)

print(o)

b'SecretKey'

Explanation:

• hexadecimal string "5365637265744b6579" represents the ASCII encoding of "SecretKey".
• bytes.fromhex(s) converts this hex string into the bytes object: b'SecretKey'.
• output of print(o) is b'SecretKey', showing the decoded string as bytes.